Instruments and methods for spinal implant revision

ABSTRACT

Instruments and methods are provided for re-positioning and extracting spinal implants in a space between vertebrae. The instruments can include rotater instruments, hook instruments, and extractor instruments engageable to the implant.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 11/523,408 filed on Sep. 19, 2006, which is incorporated hereinby reference in its entirety.

BACKGROUND

Normal intervertebral discs between endplates of adjacent vertebraedistribute forces between the vertebrae and cushion vertebral bodies.The spinal discs may be displaced or damaged due to trauma, disease oraging. A herniated or ruptured annulus fibrosis may result in nervedamage, pain, numbness, muscle weakness, and even paralysis.Furthermore, as a result of the normal aging processes, discs dehydrateand harden, thereby reducing the disc space height and producinginstability of the spine and decreased mobility. Most surgicalcorrections of a disc space include a discectomy, which can be followedby restoration of normal disc space height and bony fusion of theadjacent vertebrae to maintain the disc space height.

Other procedures can involve removal of one or more vertebral bodies asa result of trauma, disease or other condition. An implant can bepositioned between intact vertebrae to provide support until fusion ofthe affected spinal column segment is attained.

Access to a damaged disc space or to a corpectomy location may beaccomplished from several approaches to the spine. One approach is togain access to the anterior portion of the spine through a patient'sabdomen. A posterior or lateral approach may also be utilized.Postero-lateral, antero-lateral and oblique approaches to the spinalcolumn have also been employed to insert implants. Whatever theapproach, there may be a need to re-position and/or extract implantsafter positioning in the spinal disc space or corpectomy location. Thereremains a need for improved instruments and techniques for use in anyapproach that facilitate revision of spinal implants in a space betweenvertebrae.

SUMMARY

There are provided instruments and methods useful for implantre-positioning and extraction from any approach to the spine. Suchimplants can be employed in disc replacement and/or vertebral bodyreplacement type procedures. The instruments can be provided in a kit toprovide the surgeon a variety of instrument options during theprocedure.

In one aspect, an assembly for spinal implant revision includes arotater instrument with an elongate shaft extending along a longitudinalaxis, a proximal handle extending from a proximal end of the shaft, anda distal end member at a distal end of the shaft. The distal end memberincludes a first foot including a first width extending from thelongitudinal axis and a second foot including a second width less thanthe first width extending from the longitudinal axis in a directionopposite the first foot. The distal end member includes a concave distalend wall extending along the first and second feet. The assembly alsoincludes an implant sized and shaped for positioning in a space betweenvertebrae that includes a wall and at least a portion of the wall has aconvex shape that corresponds to a shape of the concave distal end wall.

In another aspect, an assembly for spinal implant revision includes anelongate shaft extending along a longitudinal axis, a proximal handleextending from a proximal end of the shaft, and a distal hook memberextending distally from the shaft. The hook member includes an elongatearm extending along the longitudinal axis and a hooked end at a distalend of the arm. The assembly also includes an implant sized and shapedfor positioning in a space between vertebrae. The implant includes areceptacle and the hooked end is positioned in the receptacle inengagement with the implant.

In a further aspect, an instrument for engaging a spinal implantincludes a shaft assembly, an actuator assembly at a proximal end of theshaft assembly, and an engaging assembly at a distal end of the shaftassembly. The engaging assembly includes a support member fixedlycoupled with the shaft assembly and extending distally therefrom and aclamping member coupled with at least one of the shaft assembly and thesupport member. The actuator assembly is operably linked to the clampingmember with the shaft assembly. The clamping member is movable towardthe support member with actuation of the actuator assembly to a clampingposition for clampingly engaging the implant between the support memberand the clamping member. The support member includes an elongated bodywith a linear proximal section and a distal section angled relative tothe proximal section. The distal section includes a flange at a distalend thereof forming a proximally oriented lip extending toward theclamping member and positionable in engagement with the implant.

In another aspect, a kit for repositioning and extracting spinalimplants includes a spinal implant, a rotater instrument, at least onehook instrument and at least one extractor instrument. The rotaterinstrument includes a shaft extending along a longitudinal axis, aproximal handle and a distal end member. The distal end member includesa distal end wall with a shape to conform to a portion of a wall of theimplant. The hook instrument includes a shaft extending along alongitudinal axis between a proximal handle and a distal hook memberconfigured to engage the implant in a receptacle of the implant. Theextractor instrument includes a shaft assembly operably linking aproximal actuator assembly and a distal engaging assembly. The distalengaging assembly is operable with the actuator assembly to clampinglyengage the implant.

According to one aspect, a method for manipulating a spinal implant in aspace between vertebrae comprises: positioning a spinal implant in thespace between vertebrae; engaging the spinal implant with a hook memberat a distal end of a hook instrument; pulling the spinal implant towardan opening into the space between the vertebrae; grasping the spinalimplant with an engaging assembly of an extractor instrument; andremoving the spinal implant from the space with the extractorinstrument.

These and other aspects will also be apparent from the followingdescription and the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a plan view of vertebral space with an implant and a distalportion of a rotater instrument.

FIG. 2 is a plan view of a vertebral space with an implant and a distalportion of a hook instrument.

FIG. 3 is a plan view of a vertebral space with an implant and a distalportion of another embodiment hook instrument.

FIG. 4 is a plan view of an implant with a distal portion of anextractor instrument engaged thereto.

FIG. 5 is a plan view of an implant with another embodiment distalportion of an extractor instrument engaged thereto.

FIG. 6 is a plan view of a rotater instrument.

FIG. 7 is a plan view of a distal end portion of the rotater instrumentof FIG. 6.

FIG. 8 is a perspective view of an adjustment instrument.

FIG. 9 is a perspective view of a hook instrument.

FIG. 10 is an elevation view of a distal hook member of the hookinstrument of FIG. 9.

FIG. 11 is an end view of the hook member of FIG. 10.

FIG. 12 is a side view of another embodiment hook member.

FIG. 13 is an elevation view of an extractor instrument.

FIG. 14 is an exploded perspective view of the extractor instrument ofFIG. 13.

FIG. 15 is an elevation view of a mounting assembly of the extractorinstrument of FIG. 13.

FIG. 16 is an exploded perspective view of the mounting assembly of FIG.15.

FIG. 17 is a section view along line 17-17 of FIG. 15.

FIG. 18 is a section view along line 18-18 of FIG. 16.

FIG. 19 is a section view along line 19-19 of FIG. 15.

FIG. 20 is a section view along line 20-20 of FIG. 19.

FIG. 21 is an elevation view of a trigger of the extractor instrument ofFIG. 13.

FIG. 22 is a top plan view of a rail member of the extractor instrumentof FIG. 13.

FIG. 23 is an elevation view of the rail member of FIG. 22.

FIG. 24 is a section view along line 24-24 of FIG. 22.

FIG. 25 is a section view along line 25-25 of FIG. 22.

FIG. 26 is a section view along line 26-26 of FIG. 23.

FIG. 27 is a section view along line 27-27 of FIG. 23.

FIG. 28 is a top plan view of a support member of the engaging assemblyof the extractor instrument of FIG. 13.

FIG. 29 is an elevation view of the support member of FIG. 28.

FIG. 30 is an elevation view of a clamping member of the engagingassembly of the extractor instrument of FIG. 13.

FIG. 31 is an elevation view of another embodiment extractor instrument.

FIG. 32 is an exploded perspective view of the extractor instrument ofFIG. 31.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

For the purposes of promoting an understanding of the principles of thepresent invention, reference will now be made to the embodimentsillustrated in the drawings, and specific language will be used todescribe the same. It will nevertheless be understood that no limitationof the scope of the invention is intended thereby. Any alterations andfurther modification in the described processes, systems, or devices,and any further applications of the principles of the invention asdescribed herein are contemplated as would normally occur to one skilledin the art to which the invention relates.

Instruments and techniques provide and facilitate implant re-positioningin and extraction from a space between vertebral bodies. The instrumentscan be provided in a kit to provide the surgeon with various options andcapabilities during the procedure. The instruments and techniques can beemployed in any approach to the space and with implants of any size andconfiguration. The implants can further be positioned in a spinal discspace between vertebrae or in a space provided by removal of all or aportion of one or more vertebral bodies in a corpectomy procedure. Asused herein, the space between vertebrae is intended to encompass thespace between adjacent vertebral bodies in intradiscal procedures andthe space between vertebrae provided by removal of all or a portion ofone or more vertebral bodies.

The instruments can include rotater instruments that can contact a wallof the implant to allow application of rotational and translationalforces to re-position or re-orient the implant in the space betweenvertebrae. Hook instruments are also provided that allow a receptacle inthe implant to be engaged with a hook member while the implant is in thespace. The hook instrument can then be manipulated to remove orre-position the implant. Also provided are extractors with a proximalactuating structure and a distal implant engaging assembly operable bythe proximal actuating structure to positively engage the implant. Theimplant engaging assembly can be pivotally or linearly movable to engagethe implant in the space. Slap hammers, mallets, tuning instruments andother manipulators can be employed to facilitate application ofre-positioning and removal forces adjacent the proximal ends of theinstruments.

Referring to FIG. 1, there is shown a space S adjacent vertebral body V.Implant 50 is positioned in space S. In the illustrated embodiment, apostero-lateral approach A is shown, it being understood that otherportal locations and approaches are contemplated. Implant 50 can be anintradiscal implant or a corpectomy device. Implant 50 can furtherinclude a banana or concavo-convex shape in plan view with the convexwall anteriorly oriented as shown, or any other suitable shape,including rectangular shapes, oval shapes, circular shapes, D-shapes,square shapes or irregular shapes. Implant 50 can be made from anysuitable bio-compatible material, including bone material, metals andmetal alloys, polymers, ceramics, carbon fiber, and combinationsthereof.

A distal portion of a rotater instrument 100 is shown in FIG. 1 with adistal end member 102 contacting wall 52 of implant 50 adjacent a distalside D of the space S. As used herein, the proximal side P of space S isthe side closest to the approach through which the instrument ispositioned, and distal side D of the space S is opposite the proximalside P. Distal end member 102 includes a concave end wall 104positionable in contact with implant 50 to allow application ofre-positioning forces along a portion of the wall 52 of implant 50. Anelongated shaft 106 extends proximally from end member 102 to allowremote manipulation of the implant 50, including contact with the sideof implant 50 that is located or to be located opposite the approach A.For example, pushing forces directed along the longitudinal axis of theinstrument as indicated by arrow 70 can be applied with rotaterinstrument 100 to rotate implant 50 into a desired orientation.Simultaneously or alternately, pivoting or rotational forces can beapplied as indicated by bi-directional arrow 72. The implant 50 can thusbe pivoted and translated in the space to a desired position from aninitial insertion position, or moved from an implanted position tofacilitate access and removal of implant 50 by one or more otherinstruments.

In FIG. 2 there is shown a hook instrument 140 and implant 50 insectional view. Implant 50 includes a receptacle 54 in wall 52.Receptacle 54 can extend partially or completely through wall 52. Hookinstrument 140 includes a shaft 142 and a distal hook member 144 at adistal end of shaft 142. Hook member 144 includes an arm 148 extendingto a hooked end 146 that can be engaged in receptacle 54 to engage theimplant and deliver forces to rotate or pivot it in space S, asindicated by bi-directional arrows 72, and alternately or simultaneouslydeliver forces that move implant 50 proximally in space S towardproximal side P as indicated by arrow 74.

In FIG. 2, hook member 144 includes arm 148 with a linear configurationextending to hooked end 146. In FIG. 3, another embodiment hookinstrument 160 is shown with a hook member 164 including an angledconfiguration extending to a hooked end 166. Hook member 164 includesangled arm 168 including a first proximal section 170 extending fromshaft 162 and a second distal section 172 angled relative to andextending distally from first proximal section 170 to hooked end 166.The angled arm 168 allows shaft 162 to be positioned at angles relativeto implant 50 that differ than those provided by linear hook member 144.

Referring to FIG. 4, there is shown an extractor instrument 200 engagedto implant 50′. Implant 50′ can be similar to implant 50 discussedabove, and is shown in sectional view. Implant 50′ includes wall 52′including a first receptacle 54′ along one side thereof and a secondreceptacle 58′ on or along a second side thereof. Receptacles 54′, 58′can extend through or partially into wall 52′, and can include any sizeor shape.

Extractor instrument 200 includes a shaft assembly 202 with a mountingassembly 204 and a rail assembly 240 movably mounted to mountingassembly 204. An engaging assembly 206 is provided at the distal end ofshaft assembly 202 that is movable to clampingly engage implant 50′.Mounting assembly 204 includes a mounting member 208 and engagingassembly 206 includes a distal support member 210 extending distallyfrom mounting member 208. Rail assembly 240 includes an elongated railmember 242 movable along mounting member 208 and engaging assembly 206includes a distal clamping member 244 movably coupled to rail member242. A linking portion 245 pivotally links clamping member 244 with oneof support member 210 and mounting member 208. Longitudinal displacementof rail member 242 with a proximal actuating assembly (discussed furtherbelow) as indicated by bi-directional arrow 76 pivots clamping member244 into and out of engagement with implant 50′ as indicated bybi-directional arrow 78. Clamping member 244 works in conjunction with aflanged end 212 of support member 210 to clampingly engage implant 50′therebetween with flanged end 212 in receptacle 58′ and clamping member244 in receptacle 54′. With the implant 50′ so engaged, implant 50′ canbe pivoted, rotated, translated and/or extracted from space S withextractor instrument 200.

In FIG. 5, there is shown another embodiment extractor instrument 400that includes a shaft assembly 402 with a mounting assembly 404 and arail assembly 440 movably mounted to mounting assembly 404. An engagingassembly 406 is provided at the distal end of shaft assembly 402 that islongitudinally movable to clampingly engage implant 50′. Mountingassembly 404 includes a mounting member 408 and engaging assembly 406includes a distal support member 410 extending distally from mountingmember 408. Rail assembly 440 includes an elongated rail member 442movable along mounting member 408 and engaging assembly 406 includes adistal clamping member 444 that moves longitudinally with rail member442 as indicated by bi-direction arrow 80 with a proximal actuatingassembly (discussed further below.) Clamping member 444 works inconjunction with a flanged end 412 of support member 410 to clampinglyengage implant 50′ therebetween with flanged end 412 in receptacle 58′and clamping member 444 axially received in a receptacle 56′ in wall52′. With the implant 50′ so engaged, implant 50′ can be pivoted,rotated, translated and/or extracted from space S with extractorinstrument 400.

Referring now to FIGS. 6 and 7, further details of rotater instrument100 will be discussed. Rotater instrument 100 includes elongated shaft106 including a proximal handle 108 and distal end member 102 at adistal end of shaft 106 opposite handle 108. Distal end member 102includes distally oriented end wall 104. Shaft 106 can include a distalshaft portion 112 extending along longitudinal axis 110 and a proximalshaft portion 114 offset from axis 110 with a pair of bends 116, 117 andan oblique shaft portion 118 extending obliquely to distal and proximalshaft portions 112, 114. The offset can facilitate viewing of distal endmember 102 and the implant in contact therewith by positioning handle108 out of the field of view. Handle 108 can be removably engaged toshaft 106 or formed integrally therewith. Embodiments with a non-offsetshaft configuration are also contemplated.

In FIG. 7, distal end member 102 is shown and includes opposite feet120, 122 extending in opposite directions from longitudinal axis 110. Inthe illustrated embodiment, first foot 120 extends outwardly a firstwidth W1 and second foot 122 extends outwardly a second width W2. In oneembodiment, width W1 is about 50% greater than width W2, although otherarrangements are contemplated ranging from a difference of about 0% to adifference of about 100% or more. In addition, end member 102 includesfeet 120, 122 that diverge distally from one another along an angle A1.Foot 120 extends along an angle A2 measured from longitudinal axis 110that is less than the angle of foot 122 from longitudinal axis 110. Inone embodiment, angle A1 is 90 degrees and angle A2 is 35 degrees. Otherangular arrangements are also contemplated. The differing widths andangular relationships can facilitate pivoting movement of the implant byallowing the greater width foot 120 to pivot the implant toward thedirection of shorter foot 122 without obstruction by the shorter foot122.

End wall 104 can be concave and extend along an arc defined by a radiusR. Radius R can be offset from axis 110 by a distance D1, althoughalignment of the center of radius R along axis 110 is also contemplated.Arc A can be provided with a shape to generally conform to a curvatureof a wall portion of the implant to be contacted with end wall 104 tofacilitate control of the implant and distribution of re-positioningforces over a larger surface area of the implant. Other embodimentscontemplate other configurations for end wall 104, including a concaveshape formed by linear and/or angular wall portions and implants withwall portions generally conforming in shape thereto.

FIG. 8 shows a tuning instrument 300 with a proximal handle 302, anintermediate shaft 304 and a distal instrument engaging structure 306.Engaging structure 306 includes a forked shape with a receptacle 308between arms 310, 312 that can receive a shaft of an instrument. Asdiscussed further below, arms 310, 312 can contact an adjustment memberof the instrument to facilitate application of re-positioning andextraction forces to the instrument by manipulating tuning instrument300, and thus tune or adjust the position of the implant in contact withthe instrument.

In FIG. 9 there is shown hook instrument 140. Hook instrument 140includes shaft 142 and hook member 144 at a distal end of shaft 142.Shaft 142 extends along longitudinal axis 143. Hook instrument 140further includes a proximal handle 150 at a proximal end of shaft 142and an adjustment member 152 extending outwardly from shaft 142 distallyof handle 150. Adjustment member 152 can be contacted with an adjustmentmember, such as tuning instrument 300, at the proximal or distal sidesthereof to facilitate application of adjustment forces to hookinstrument 140 and thus to an implant engaged thereby.

Hook member 144 is shown in further detail in FIGS. 10 and 11. Hookmember 144 includes a linear arm 148 extending and centered alonglongitudinal axis 143. Hook member 144 includes a proximal end member154 that is engageable to shaft 142 by a press fit and epoxy or othersuitable engagement structure or means, including fasteners, welding andthe like. Hooked end 146 includes a first hook portion 146 atransversely oriented to longitudinal axis 143 and linear arm 148, and asecond hook portion 146 b that extends from first hook portion 146 aproximally and generally parallel to longitudinal axis 143. Hookedportion 146 b is spaced from arm 148 to provide a space to engage theimplant in hooked end 146. In one embodiment, first hook portion 146 aincludes a length L1 that is about 50% greater than a length L2 ofsecond hook portion 146 b. The lengths L1 and L2 can facilitatepositioning of hooked end 146 in a receptacle and in engagement to theimplant with the implant in space S while minimizing intrusion of hookinstrument 140 into the adjacent tissue during engagement anddisengagement with the implant. Other embodiments contemplate otherrelationships between the length of hook portions 146 a, 146 b,including lengths that are the same and lengths where hook portion 146 bhas a length greater than hook portion 146 a.

As shown in FIG. 11, hooked end 146 can include a square-shapedcross-section to facilitate engagement with the implant in a manner thatprevents or reduces rotation of the hooked end relative to the implant.Other embodiments contemplate other shapes for hooked end 146 and arm148, including circular, rectangular, oval, polygonal, and non-circularshapes.

Referring now to FIG. 12, there is shown hook member 164, it beingunderstood that hook instrument 160 could be provided with a shaft andhandle structure like that discussed above for hook instrument 140. Hookmember 164 includes angled arm 168 including proximal section 170extending along longitudinal axis 163. Distal section 172 is angledrelative to longitudinal axis 163 and proximal section 170 at an angleA2. In one embodiment, angle A2 is about 45 degrees, although otherangular relationships are contemplated. The angular relationshipfacilitates positioning of the hook member 164 around a curved portionor bend of the implant body while minimizing intrusion of the hookmember 164 into the adjacent tissue. Distal section 172 can have alength L3 extending to hooked end 166. Hooked end 166 includes a firstportion 166 a extending transversely to distal section 172 along alength L4 and a second portion 166 b extending proximally from an end offirst portion 166 a along length L5 in a generally parallel and spacedrelationship to distal section 172. In the illustrated embodiment,length L3 is greater than length L4 which is greater than length L5.Other arrangements contemplate other relationships between lengths L3,L4 and L5.

In FIGS. 13 and 14, there is shown extractor instrument 200 includingshaft assembly 202 with mounting assembly 204 and rail assembly 240mounted to mounting assembly 204. Engaging assembly 206 is provided atthe distal end of shaft assembly 202 and is movable with an actuatingassembly 270 to clampingly engage an implant. Mounting assembly 204includes mounting member 208 and rail assembly 240 includes an elongatedrail member 242 movable along mounting member 208. Engaging assembly 206includes distal support member 210 fixedly engaged to and extendingdistally from mounting member 208 and distal clamping member 244 movablycoupled to rail member 242 with a first pin 298. Clamping member 244includes a proximal linking portion 245 pivotally coupled with supportmember 210 with second pin 299. Longitudinal displacement of rail member242 with proximal actuating assembly 270 translates pin 298 alongclamping member 244 and pivots clamping member 244 about pin 299 intoand out of engagement with the implant. Clamping member 244 works inconjunction with a flanged end 212 of support member 210 to clampinglyengage the implant therebetween for re-positioning in and/or extractionof the implant from the space S with extractor instrument 200.

Referring further to FIGS. 15 and 16, further details of mountingassembly 204 are provided. Mounting member 208 includes an elongatedbody extending between a distal end 214 and a proximal handle structure216. An adjustment member 220 is provided extending proximally fromhandle structure 216 for engagement with an adjustment instrument, suchas a slap hammer. An intermediate housing portion 218 is providedbetween handle structure 216 and mounting member 208. Housing portion218 is configured for engagement with a trigger 272 of actuatingassembly 270.

As shown in FIG. 21, trigger 272 includes a hand-hole portion 274 and anupper arm 276. Upper arm 276 includes a groove 278 and a central hole280 extending therethrough. A locking hole 282 is provided betweenhand-hole portion 274 and central hole 280. Locking hole includes athrough slot 282 a and a recessed portion 282 b extending about andoff-center relative to slot 282 a along one side of upper arm 276.Hand-hole portion 274 is sized to receive one or more fingers of theuser's hand. Other arrangements for trigger 272 are also contemplated,such as where no hole is provided and one or more fingers of the user'shand extend around the trigger.

Referring now to FIG. 17, housing portion 218 includes a central slot222 extending therethrough to receive arm 276 of trigger 272. Housingportion 218 further includes a first bore 224 to receive a mounting pin290 (FIG. 14) through central hole 280 to pivotally couple trigger 272to housing portion 218. In the illustrated embodiment, one side of bore224 is threaded to threadingly engage mounting pin 290 while hole 280 issized to allow rotation of trigger 272 about mounting pin 290. Housingportion 218 also includes a second bore 226 configured to receive aspring loaded locking pin 292, spring 294, and locking button 296.Locking button 292 includes a first portion 292 a that is positioned inslot 282 a in a manner that allows trigger 272 to be pivoted aboutmounting pin 290 to a position that engages the implant with engagingassembly 206. In this engaged position, a second, enlarged portion 292 bof locking pin 292 is aligned with recess 282 b, and spring 294 biasesthe enlarged portion 292 b into recess 282 b to lock trigger 272 andthus engaging assembly 206 to the implant. When it is desired to releasethe implant, button 296 can be pressed to force the enlarged portion 292b out of recess 282 b and orient first portion 292 a in slot 282 a sothat the trigger can move back along first portion 292 a to thedisengaged position.

Mounting member 208 further includes a proximal inverted T-shapedlongitudinal slot 228 as shown in FIGS. 18 and 20 extending therealongand opening along an upper surface thereof proximally of central slot222 to receive a proximal rail portion of rail member 242, as discussedfurther below. As shown in FIGS. 19 (with support member 210 removed)and 20, mounting member 208 includes a distal inverted T-shapedlongitudinal slot 230 extending therealong adjacent distal end 214 to adistal rail portion of rail member 242, as discussed further below.Mounting member 208 also includes a bottom groove 232 adjacent distalend 214 that can receive support member 210, as discussed further below.

Referring now to FIGS. 22-23 there is shown rail member 242. Rail member242 includes an elongated body extending between a distal mountingportion 246 and a proximal mounting portion 248. As shown further inFIG. 24, distal mounting portion 246 includes a pair of fingers 250including holes 252 therethrough to receive mounting pin 298 to coupleclamping member 244 to distal mounting portion 246. Second mounting pin299 pivotally couples clamping member 244 to support member 210. Asshown in FIG. 26, an inverted T-shaped rail portion 255 extends downfrom rail member 242 along distal mounting portion 246. Rail portion 255is positionable in distal longitudinal slot 230 to secure rail member242 along mounting member 208 while permitting longitudinal slidingmovement therebetween. As shown in FIG. 27, proximal mounting portion248 further includes a proximal T-shaped rail portion 262 that isslidably received in proximal longitudinal slot 228 of mounting member208 while permitting longitudinal sliding movement therebetween.

Referring further to FIGS. 25 and 27, proximal mounting portion 248 willbe further discussed. Proximal mounting portion 248 includes a body thatincreases in cross-sectional width and height to provide increasedstrength and stability along proximal mounting portion 248. Proximalmounting portion 248 includes an intermediate projection 256 extendingtherefrom that is received in a distal portion 223 (FIG. 20) of centralslot 222 of housing portion 218. There is further provided a recessedarea 258 including side holes 260 to receive a pin 261 (FIG. 13) that ispositioned in groove 278 of trigger 272 (FIG. 21). Trigger 272 can pivotabout pin 261 while upper arm 276 is movable in recessed area 258. Pin261 assists in maintaining the desired orientation and positioning oftrigger 272 relative to mounting portion 248. In addition, spring member286 is positioned in distal portion 223 of central slot 222 and distallyof intermediate projection 256. Spring member 286 contacts a distal endwall 225 (FIG. 20) of distal portion 223 and extends to a proximal endthat contacts projection 256 to proximally bias rail member 242. Spring286 also proximally biases upper arm 276 of trigger 272 about mountingpin 290 since trigger 272 is coupled to rail member 242 with pin 261.Spring 286 normally biases engaging assembly 206 to an open position.When trigger 272 is squeezed, rail member 242 is distally displacedagainst the bias of spring 286 by the upper arm 276 rotating aboutmounting pin 90 and displacing rail member 242 through its engagementthereto with the pin 261 in side holes 260.

Referring now to FIGS. 28 and 29, there is shown support member 210.Support member 210 includes a proximal tongue 320 configured forpositioning in bottom groove 232 of mounting member 208 and securabletherein with a press fit, epoxy, welding, fasteners and/or othersuitable connecting arrangements. Support member 210 further includes abody portion 322 with a central slot 324 and side holes 326 to receivemounting pin 299 (FIG. 14). Body 322 includes a linear proximal section323 and a distal section 325 angled relative to proximal section 323toward clamping member 244. Support member 210 includes flange 212 atthe distal end of distal section 325 that extends toward clamping member244. Flange 212 forms a proximally oriented lip 213 that extends towardclamping member 244. The fixed relationship of support member 210 andangled body 322 facilitates placement of support member 210 into thespace and around the implant without bending or pivoting of supportmember 210 so flange 212 can engage a receptacle in the implant.

In FIG. 30 there is shown clamping member 244 with proximal linkingportion 245 including a through-hole 330 to receive mounting pin 299 andpivotally couple clamping member 244 in slot 324 of support member 210.Clamping member 244 includes an angled portion 336 extending fromlinking portion 245. Angled portion 336 includes an angled slot 332through which pin 298 extends. Slot 332 includes a proximal end 332 aand a distal end 332 b that are both offset toward support member 210when assembled thereto. Slot 332 defines an arcuate path angled awayfrom support member 210 at a mid-portion thereof between ends 332 a, 332b that is configured to provide positive seating of flange 334 with areceptacle or other structure of the implant. Clamping member 244further includes an extension portion 338 that forms a concave recess340 therealong oriented toward support member 210 to facilitatepositioning of clamping arm 244 around the implant. Flange 334 isprovided at the distal end of extension portion 338, and forms aproximally oriented lip 342 positionable in contact with the implant inconjunction with the proximally oriented lip formed by flange 212. Thelips 213, 342 axially restrain the implant to engaging assembly 206during re-positioning and extraction of the implant.

When assembled as shown in FIG. 13, trigger 272 is movable tolongitudinally and distally displace upper rail member 242 of railassembly 240 against the bias of spring 286. This movement in turn movespin 298 along slot 332 of clamping member 244 from proximal end 332 atoward distal end 332 b. Clamping member 244 in turn pivots about itsengagement with support member 210 so that flanged end 334 moves towardflanged end 212, clamping the implant therebetween with engagingassembly 206. The clamped engagement can be maintained by locking pin292 positively engaging trigger 272 in the closed position. A slaphammer, tuning fork or other instrument can be engaged to adjustmentmember 220 to facilitate application of re-positioning and/or removalforces to move the implant in space S. When the implant has beenre-positioned or removed, the trigger 272 can be unlocked by depressingbutton 296 to displace locking pin 292 relative to the trigger 272, andspring 286 biases rail member 242 proximally to pivot clamping member244 away from support member 210 and release the implant from engagingassembly 206.

Referring to FIGS. 31-32, there is shown another embodiment extractorinstrument 400 that is similar to extractor instrument 200, except thatengaging assembly 406 does not include a pivoting arrangement but rathera longitudinal sliding arrangement. Trigger 472 is pivotally coupledwith mounting assembly 402 with mounting pin 490 and linked to upperrail member 442 of rail assembly 440 with pin 443. Rail member 442 canbe secured to and longitudinally movable along mounting member 408 witha rail and slot arrangement in a manner similar to that discussed abovewith respect to extractor instrument 200, except that there is noproximal spring bias of rail member 442, although such is not precluded.Mounting member 408 includes a support member 410 of engaging assembly406 extending distally therefrom. Support member 410 can be configuredlike support member 210 discussed above, but does not include any slotto receive clamping member 444.

Upper rail member 442 includes clamping member 444 in the form of acylinder with a rounded distal end formed by a bullet or ball-shaped tipthat can be positioned in an implant receptacle. In use, support member410 is positioned along one side of the implant with the hooked end inengagement with an implant receptacle. Trigger 472 is squeezed todistally and longitudinally displace rail member 442 and thus clampingmember 444 toward the implant. When clamping member 444 is positioned inthe implant receptacle, the implant is clamped between support member410 and clamping member 444, and extraction or re-positioning of theimplant can be performed with extractor instrument 400 as discussedabove with respect to extractor instrument 200.

It is contemplated that the above-described instruments and methods canbe used in substantially open surgical procedures. It is alsocontemplated that the instruments and methods may be utilized throughguide sleeves or tubes. Sleeves and tubes can provide greater protectionto adjacent tissues, reduce the size of access incisions, provide directvisualization of the surgical site, and/or provide enhanced control ofthe procedure. The instruments and methods may further be used incombination with disc space preparation and implant insertion throughmicroscopic or endoscopic instruments that provide direct visualizationof the surgical site.

The instruments discussed herein are suited for re-positioning andextracting an implant in a space between vertebrae for revisionprocedures. The rotater and hook instruments provide the surgeon theability to re-position an implant in the space to a desired implantationorientation, or to re-position the implant for engagement with one ofthe extractor instruments. The rotater instruments can pivot andtranslate the implant in the disc space with a pushing force applied bymanipulating the handle manually or with a mallet or other instrument.The hook instruments can re-position the implants by pivoting andpulling either manually or with supplemental instruments, such as withthe tuning instrument. The extractor instruments can be employed tore-position the implants, or to remove the implants for anotherinsertion attempt. The instruments can also be employed in revisionprocedures where a second surgical procedure is performed to access andre-position or remove the implant.

The re-positioning and extraction instruments can be provided in a kit,either separately or along with instruments for positioning the implantsin the space between vertebrae. The kit can include a spinal implantwith a wall defining a size and shape for positioning between vertebraeand at least one receptacle in the wall. The kit can also include arotater instrument including a shaft extending along a longitudinal axisbetween a proximal handle and a distal end member that has a distal endwall with a shape to conform to a portion of the wall of the implant.The kit can also include a hook instrument that includes a shaftextending along a longitudinal axis between a proximal handle and adistal hook member configured to engage the implant in the at least onereceptacle. The kit can further include an extractor instrumentincluding a shaft assembly operably linking a proximal actuator assemblyand a distal engaging assembly that is operable with the actuatorassembly to clampingly engage the implant.

In one embodiment, the kit can also include a second hook instrumentwith a shaft extending along a longitudinal axis between a proximalhandle and a distal hook member that is configured to engage the implantin the at least one receptacle. One of the hook members in the kitincludes a linear arm extending from the shaft to a distal hooked endand the other of the hook members includes an angled arm extending fromthe shaft to a distal hooked end.

In another embodiment, the engaging assembly of the extractor instrumentin the kit includes a clamping member movable with the actuator assemblyand a support member fixed to the shaft assembly. In one form, theclamping member is movable longitudinally with the actuator assembly toclampingly engage said implant between said clamping member and saidsupport member. In another form, the clamping member is pivotallymovable with the actuator assembly to clampingly engage the implantbetween the clamping member and the support member.

In a further embodiment, the distal end wall of the rotater instrumentin the kit includes a concave curvature extending transversely to thelongitudinal axis.

In yet another embodiment, the kit can include a tuning instrumenthaving a forked end. The hook instrument includes an adjustment memberextending outwardly from the shaft, and the forked end is sized forpositioning about the shaft of the hook instrument in contact with theadjustment member.

While the invention has been illustrated and described in detail in thedrawings and the foregoing description, the same is considered to beillustrative and not restrictive in character. All changes andmodifications that come within the spirit of the invention are desiredto be protected.

1. An assembly for spinal implant revision, comprising: an elongateshaft extending along a longitudinal axis; a proximal handle extendingfrom a proximal end of said shaft; a distal end member at a distal endof said shaft, said distal end member including a first foot including afirst width extending from said longitudinal axis and a second footincluding a second width extending from said longitudinal axis in adirection opposite said first foot, said first width being greater thansaid second width; a concave distal end wall extending along said firstand second feet; and an implant sized and shaped for positioning in aspace between vertebrae and including a wall and at least a portion ofsaid wall including a convex shape that corresponds to a shape of saidconcave distal end wall.
 2. The assembly of claim 1, wherein said distalend wall is concavely curved along said first and second feet.
 3. Theassembly of claim 2, wherein said concavely curved distal end wallextends along an arc defined by a radius.
 4. The assembly of claim 1,wherein said first and second feet diverge distally relative to oneanother and away from said longitudinal axis along an angle extendingbetween said feet.
 5. The assembly of claim 4, wherein said angle is 90degrees.
 6. The assembly of claim 4, wherein said first foot extendsdistally along a first angle measured from said longitudinal axis andsaid second foot extends distally along a second angle measured fromsaid longitudinal axis, said first angle being substantially less thansaid second angle.
 7. The assembly of claim 1, wherein said shaftincludes a distal portion along said longitudinal axis and a proximalportion offset from said longitudinal axis and extending generallyparallel to said distal portion.
 8. An assembly for spinal implantrevision, comprising: an elongate shaft extending along a longitudinalaxis; a proximal handle extending from a proximal end of said shaft; adistal hook member extending distally from said shaft, said hook memberincluding an elongate arm extending along said longitudinal axis and ahooked end at a distal end of said arm; and an implant sized and shapedfor positioning in a space between vertebrae, said implant including areceptacle and said hooked end is positioned in said receptacle inengagement with said implant.
 9. The assembly of claim 8, furthercomprising an adjustment member extending outwardly from said shaftdistally of said handle.
 10. The assembly of claim 9, further comprisinga tuning instrument including a fork-shaped end positionable about saidshaft in contact with said adjustment member.
 11. The assembly of claim8, wherein said hook member includes a linear arm extending along saidlongitudinal axis and said hooked end includes a first portion extendingtransversely to said arm to a second portion of said hooked endextending proximally from said first portion in a generally parallelrelationship with said linear arm.
 12. The assembly of claim 8, whereinsaid hook member includes an angled arm including a proximal sectionextending along said longitudinal axis and a distal section obliquelyoriented to said proximal section, wherein said hooked end extends froma distal end of said distal section.
 13. The assembly of claim 12,wherein said hooked end includes a first portion extending transverselyto said distal section to a second portion of said hooked end, saidsecond portion extending proximally from said first portion in parallelrelation to said distal section of said angled arm.
 14. The assembly ofclaim 8, wherein said hook member includes a square cross-section alongat least said hooked end. 15-28. (canceled)
 29. A method formanipulating a spinal implant in a space between vertebrae, comprising:positioning a spinal implant in the space between vertebrae; engagingthe spinal implant with a hook member at a distal end of a hookinstrument; pulling the spinal implant toward an opening into the spacebetween the vertebrae; grasping the spinal implant with an engagingassembly of an extractor instrument; and removing the spinal implantfrom the space with the extractor instrument.
 30. The method of claim29, further comprising: pivoting the spinal implant in the space to adesired orientation in the space with a rotater instrument.
 31. Themethod of claim 29, wherein pulling the spinal implant includes pivotingthe spinal implant with the hook instrument.
 32. The method of claim 29,wherein engaging the spinal implant with the hook member includespositioning the hook member in a receptacle in a wall of the spinalimplant.
 33. The method of claim 32, wherein engaging the spinal implantwith the hook member includes selecting between a first hook instrumentwith a hook member formed by a linear arm and a hooked end at a distalend of said linear arm and a second hook instrument with a hook memberformed by an angled arm and a hooked end at a distal end of said angledarm.
 34. The method of claim 29, wherein grasping the spinal implantwith the engaging assembly includes positioning a support member of theengaging assembly in a receptacle of the spinal implant and linearlyadvancing a clamping member into a second receptacle of the spinalimplant to clampingly engage the spinal implant between the supportmember and the clamping member.
 35. (canceled)